Why would you configure root protection?

A.
You want to protect the root bridge from receiving BPDUs on unauthorized interfaces.

B.
You want to protect your network from unwanted topology changes from a rogue switch attempting to become the root bridge.

C.
You want to avoid a broadcast storm that originates on the root bridge.

D.
You want to prevent unwanted user authentication to the root bridge by defining an acceptable source-address list for authorized access.